Ultra low NOx water heater

Abstract

A low NO x water heater including a water container; a combustion chamber adjacent the water container having an opening covered with an open flame arrestor; a burner associated with the combustion chamber and arranged to combust fuel to heat water in the water container, the burner including a plenum chamber having a combustion surface and a fuel/air conduit adapted to receive fuel and air and extending between and sealed to the plenum and a wall of the combustion chamber; and a heat resistant acoustic absorber positioned on the wall.

1 . A low NO x  water heater comprising: 
 a water container;    a combustion chamber adjacent the water container having an opening covered with an open flame arrestor;    a burner associated with the combustion chamber and arranged to combust fuel to heat water in the water container, the burner comprising a plenum chamber having a combustion surface and a fuel/air conduit adapted to receive fuel and air and extending between and sealed to the plenum and a wall of the combustion chamber; and    a heat resistant acoustic absorber positioned on the wall.    
   
   
       2 . The water heater defined in  claim 1 , wherein the wall is substantially vertically oriented and the absorber is adhered to the wall.  
   
   
       3 . The water heater defined in  claim 2 , wherein the absorber extends vertically between a bottom portion of the water container and a bottom portion of the water heater.  
   
   
       4 . The water heater defined in  claim 1 , wherein the absorber is an insulation pad.  
   
   
       5 . The water heater defined in  claim 1 , wherein the absorber comprises fiberglass.  
   
   
       6 . The water heater defined in  claim 1 , further comprising a metallic backing layer applied to the absorber.  
   
   
       7 . A low NO x  water heater comprising: 
 a water container;    a combustion chamber adjacent the water container;    a burner associated with the combustion chamber and arranged to combust fuel to heat water in the water container, the burner having a combustion surface and a fuel/air conduit extending from the plenum and adapted to receive fuel; and    a fuel nozzle positioned to supply fuel into the fuel/air conduit at an angle that is between about 1.5° and about 2.5° out of horizontal relative to a horizontal plane extending along a central axis of the fuel/air conduit.    
   
   
       8 . The water heater defined in  claim 7 , wherein the angle is about 2°.  
   
   
       9 . The water defined in  claim 7 , wherein an end portion of the fuel/air conduit extending from the plenum is sealed to a wall portion of the combustion chamber.  
   
   
       10 . The water heater defined in  claim 9 , wherein the wall portion is a door sealed to an opening in the combustion chamber.  
   
   
       11 . The water heater defined in  claim 7 , wherein the fuel/air conduit extends into the plenum a distance of about ¾ of the length of the plenum.  
   
   
       12 . The water heater defined in  claim 11 , wherein a distal portion of the fuel/air conduit extending into the plenum is angled at about 45°.  
   
   
       13 . A low NO x  water heater comprising: 
 a water container;    a combustion chamber adjacent the water container having an opening covered with an open flame arrestor;    a burner associated with the combustion chamber and arranged to combust fuel to heat water in the container, the burner having a combustion surface and adapted to receive fuel; and    a fuel/air conduit sealed between a wall portion of the combustion chamber and the plenum, wherein an end portion of the conduit adjacent the wall portion is substantially conically shaped.    
   
   
       14 . The water heater defined in  claim 13 , wherein the end portion further comprises a flange connected to the conically shaped portion and the flange is located exteriorly of the wall portion and is sealed to the wall portion.  
   
   
       15 . The water defined in  claim 13 , wherein the wall portion is a door sealed to an opening in the combustion chamber.  
   
   
       16 . The water heater defined in  claim 13 , wherein the fuel/air conduit extends into the plenum a distance of about ¾ of the length of the plenum.  
   
   
       17 . The water heater defined in  claim 13 , wherein a distal portion of the fuel/air conduit extending into the plenum is angled at about 45°.  
   
   
       18 . A low NO x  water heater comprising: 
 a water container;    a combustion chamber adjacent the water container;    a burner associated with the combustion chamber and arranged to combust fuel to heat water in the water container, the burner comprising a plenum chamber having a combustion surface and a fuel/air conduit adapted to receive fuel and air and extending between and sealed to the plenum and a wall of the combustion chamber; and    a heat resistant acoustic absorber positioned on the wall.    
   
   
       19 . The water heater defined in  claim 18 , wherein the wall is substantially vertically oriented and the absorber is adhered to the wall.  
   
   
       20 . The water heater defined in  claim 19 , wherein the absorber extends vertically between a bottom portion of the water container and a bottom portion of the water heater.  
   
   
       21 . The water heater defined in  claim 18 , wherein the absorber is an insulation pad.  
   
   
       22 . The water heater defined in  claim 18 , wherein the absorber comprises fiberglass.  
   
   
       23 . The water heater defined in  claim 18 , further comprising a metallic backing layer applied to the absorber.